. ♪ chevron has been developing energy here for decades. we need to protect their environment. we have a strict quarantine system to protect the integrity of the environment. forty years on, it's still a class-a nature reserve. it's our job to look after them. ...it's my job to look after it. ♪ >>> welcome back. keeping them honest, tonight we wanted to know how it's possible that a man can be killed, run down by a car, possibly on purpose, possibly because of the color of his skin, and nothing whatsoever be done about it. his name was garrett burdette, he was killed, likely run over by a car or truck in mississippi. happened three and a half years ago. three and a half years ago. ever since, until our drew griffin got involved, authorities have done precisely nothing to investigate his death. nothing, that is, except leave the public, victim's mother included, with the mistaken impression that they were on top of it, that they actually were investigating when they weren't. here's part of drew griffin's report. >> reporter: did they ever come up and down these streets handing